[ovs-discuss] ifindex of datapath
motonori at shin.do
Wed Nov 26 23:24:27 UTC 2014
Oh I din’t come up with this idea. Thanks a lot!
As to the current Engine ID and Engine Type, I agree with you. There must be a better way, or simply defaults to 0 regardless to the type of datapath as we can explicitly set these values anyway.
2014/11/27 1:53、Ben Pfaff <blp at nicira.com> のメール：
> On Wed, Nov 26, 2014 at 11:01:57PM +0900, Motonori Shindo wrote:
>> Is there any way to know the ifindex of datapath (ova-system) by using
>> ovs-vsctl/dpctl/appctl ?
> "cat /sys/class/net/ovs-system/ifindex" will show you, although I
> understand it is not one of the tools you mention.
>> I also noticed that switch.xml says:
>> <column name="engine_id">
>> Engine ID to use in NetFlow messages. Defaults to datapath index
>> if not specified.
>> <column name="engine_type">
>> Engine type to use in NetFlow messages. Defaults to datapath
>> index if not specified.
>> but this is only true in the case of netlink. If OVS is run in user
>> space these are derived from the hash based on datapath name, I think.
> Here's some better documentation of the current situation, but the
> current situation just looks crazy to me. I think we should probably do
> something different:
> <column name="engine_id">
> Engine ID to use in NetFlow messages. The value used depends on
> the datapath in use. Kernel-based datapaths use the ifindex of
> the datapath device, e.g. the ifindex of <code>ovs-system</code>
> (this can change from one boot to the next or even more often if
> the Open vSwitch kernel module is unloaded and reloaded or if
> the datapath is otherwise deleted). The userspace datapath uses
> 8 bits of an internally generated hash of the datapath name (for
> a given Open vSwitch architecture and version, this is a
> <column name="engine_type">
> Engine type to use in NetFlow messages. The value used depends
> on the datapath in use. Kernel-based datapaths use the ifindex
> of the datapath device (the same value as <ref
> column="engine_id"/>. The userspace datapath uses 8 bits of an
> internally generated hash of the datapath name (but the bits
> used are different from <ref column="engine_id"/>.
More information about the discuss